Two bomb attacks killed at least four people Tuesday in Pakistan's northwest tribal region of Khyber.

In the first blast, two paramilitary officers and at least one civilian member of a peace committee were killed when a roadside bomb exploded in the village of Painda Cheena.

As people tried to assist the victims of the initial blast, a second bomb exploded, killing one person and injuring several others.

No group has claimed responsibility for the bombings.

Thousands of people have fled the Khyber area since the Pakistani military launched an operation last month to root out suspected militants. Authorities suspect Islamist fighters fleeing the Waziristan offensive have taken refuge there.

The army says more than 1,100 militants have been killed since the start of the Waziristan offensive in June. The military says it has cleared major towns of extremist networks accused of carrying out deadly attacks on both sides of the Pakistan-Afghanistan border.